1. Field of the Invention
The invention relates to thermoplastic molding materials based on impact resistant polystyrene and polyphenylene ethers. More particularly, this invention relates to a thermoplastic molding material containing an impact resistant polystyrene and a polyphenylene ether wherein the impact resistant polystyrene is a mixture of an impact resistant polystyrene containing a flexible component having a glass temperature below -70.degree. C. and an impact resistant polystyrene containing a flexible component having a glass temperature in the range of from 0.degree. C. to 70.degree. C.
2. Description of the Prior Art
Thermoplastic masses which are useful for the manufacture of molded parts and which contain impact resistant polystyrene and polyphenylene ethers are described in U.S. Pat. Nos. 3,383,435, 4,128,602 and 4,128,603. U.S. Pat. No. 4,167,507 and German Published Application No. 22 58 896 describe molding materials which also contain hydrogenated block copolymers of butadiene and styrene and/or diene rubber interpolymers for increasing the impact resistance.
Such molding materials are suited for the manufacture of molded parts which when compared with impact resistant polystyrene which are not mixed with polyphenylene ethers stand out by improved dimensional stability when exposed to heat. The material properties of such molding masses are generally satisfactory, but it has been shown that the notch impact resistance of these molding materials is not sufficient for a number of applications.